Sending RIS completion data: use HL7 ORM or ORU message?

Sending RIS completion data: use HL7 ORM or ORU message?

Hello,

In the solution i'm helping to develop we need to send procedure data
(acquired during a radiological exam) to a remote reporting partner
(RRP), so the radiologist can see the procedure data and the
radiographers comments before they start to report the exam.

The INITIAL order is sent from our PAS to the RRP (and other
endpoints) in an ORM^O01 message. This appears to be standard.

What is the right message type to use, for the procedure data? There
seem to be two options:

1) Use ORM^O01 again, but with ORC.1 = RE (revise) and the procedure
data sent in OBX segments (the HL7 standard appears to support this).
2) Use an ORU^R01 to send the procedure data.

The procedure data is really a set of observations, so I'm leaning in
the direction of (2), but the message is intended to trigger the
reporting process (whose outcome will be an ORU^R01), and may also be
used to inform other endpoints (e.g. PACS) that the exam is complete.

I'd be grateful for advice, suggestions, pointers etc.

Many thanks,
Roger Searjeant.